Barium sulfate scale formation has been experienced for many years in the petroleum industry. Its formation can prove problematic as its formation in drilling cases surrounding mud slurries and the like has impeded petroleum recovery and has caused fouling and deposit formation along drilling implements and oil recovery lines.
Barium sulfate deposition has also proved problematic in the pulp and papermaking industry. Barium is chemically bound to many types of woods and is released from the wood pulp during papermaking operations via ion exchange mechanisms. Sulfuric acid and alum (aluminum sulfate) are used extensively in papermaking, and as a result, sulfate ion concentrations can be quite high. This combination causes barium sulfate to readily precipitate in papermaking systems.
The problem does not appear to be isolated to any particular geographic region as it has been seen on groundwood machines, fine paper machines and unbleached kraft machines in all parts of the United States. Generally, deposits have been found in the screens, cleaners, fan pump, organ tubes, headbox, rectifier rolls, headbox lip and slice, and on the fourdrinier foils.
These deposits can lead to formation problems, fiber bundles or "twists" coming loose and causing holes in the sheet. Paper machine breaks can even occur due to crushouts at the presses. Deposition also provides a favorable location for sulfate reducing bacteria to fester, leading eventually to corrosion problems and subsequent papermaking problems.
Where barium sulfate deposition problems have been especially severe, dollar losses can be attributed to lost production because of off-spec paper and downtime for cleaning. Further monetary losses are due to labor and the mechanical costs of cleaning, as well as, shortened equipment life because of corroded headboxes. The problem is especially acute due to the low solubility of the compound in water.